/*
 * Copyright (c) 2007 jMouse Gestures
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'jMouse Gestures' nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.jmg.gesture.checker;

import com.jmg.gesture.Gesture;
import com.jmg.gesture.GestureMovement;
import com.jmg.mouse.MouseMovement;
import java.io.Serializable;


/**
 * ExactChecker class checks the mouse movements match the required gesture 
 * movements exactly.
 *
 * @author  Christopher Martin
 * @version $Id: ExactChecker.java 17 2007-09-28 15:00:09Z GentlemanHal $
 */
public class ExactChecker implements 
    GesturePerformedChecker,
    Serializable
{
    /** Serial Version UID. */
    private static final long serialVersionUID = 1L;
    
    
    
    

    /**
     * Checks if the given mouse movements match the given gesture.  If 
     * <code>null</code> or zero mouse movements are passed then 
     * <code>false</code> is always returned.
     * 
     * @param  gesture The gesture to check which can not be <code>null</code>.
     * @param  mouseMovements The mouse movements to check against.
     * @return <code>true</code> if the mouse movements passed matched the
     *         passed gesture, <code>false</code> otherwise.
     * @throws java.lang.IllegalArgumentException If a <code>null</code>
     *         argument for gesture is passed.
     */
    public boolean matched(Gesture gesture, MouseMovement... mouseMovements) 
        throws IllegalArgumentException
    {
        if (null == gesture) {
            throw new IllegalArgumentException("gesture was null!");
        }
        
        
        if (null == mouseMovements || 0 == mouseMovements.length) {
            return false;
        }
        
        
        GestureMovement[] movements = gesture.getMovements();
        float combinedLength = 0f;
        int   mappingIndex   = 0;
        
        for (int mouseIndex = 0; mouseIndex < mouseMovements.length; mouseIndex++) {   
            if (mappingIndex >= gesture.getNumberOfDirections()) {
                break;
            }
            
            if (movements[mappingIndex].validAngle(mouseMovements[mouseIndex].getAngle())) {   
                combinedLength += mouseMovements[mouseIndex].getLength(); 

            } else if (movements[mappingIndex].validLength(combinedLength)) {
                mappingIndex++;
                combinedLength = 0f;
                
                /* 
                 * Must check the same mouse movement against the next 
                 * gesture movement 
                 */
                mouseIndex--;

            } else {
                return false;
            }

        }
        
        /* Make sure all gesture movements were checked and the final length was valid */
        return mappingIndex == (gesture.getNumberOfDirections() - 1) &&
               movements[mappingIndex].validLength(combinedLength);
    }

}
